| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the coverlay by interposing an intermediate layer including a bonding sheet between first and second base films, each formed with a conductive circuit only on one side, and then pressing them to bond two base films. SOLUTION: A bonding sheet 10 composed of a polyimide based resin is arranged to touch, on one side, with the conductor circuit 21 side of a base film 20 and, on the other side, with the conductor circuit 31 side of a base film 30. They are then hot pressed to obtain a first laminate 40. The laminate 40 is arranged, on the opposite sides, with prepregs 23, 33. Subsequently, laminates 24, 34 are arranged, respectively, on the upper and lower surfaces of prepreg 23. They are then hot-pressed to obtain a second laminate. This method reduces the production cost greatly while preventing delamination. |
